I went to the outdoor range for the first time in a long time the other day and found myself shooting my 9mm OLY AR pretty well out to about 110yrs.  Recoil was almost non-existent and the rounds hit where you wanted them too.  I tried shooting without ear protection just to get a sense of how loud it was and it was very tame. I wouldn't shoot all day without ear protection but for a self defense situation, I can see where it would be nice to not have the deafening noise of a .223 round.  

The increased velocity from the 16 inch barrel seems like it would make the 9mm round hit a little harder, obviously not like a .223 round but seems like it would be more effective than from a pistol.

Does anyone have any thoughts on the pro's and con's of using a 9mm vs. a .223 round for self defense?

Has anyone measured penetration and velocity of the 9mm out of a 16inch barrel.

Just curious to know if you see a 9mm AR as a plinking toy or believe that is has true advantages over the .223 round.

Just for the record, I'm talking about distances between 0 and 100yrs here.  Obviously, the rifle bullet would gain a considerable advantages as range increases.

Thanks for any replies.

I just thought that one other advantage of the 9mm upper is the lack of using a gas tube which seems to cause a lot of problems in the rifle caliber AR's  

Would anyone consider the 9mm upper more durable than a .223 upper because of the fewer parts and lack of gas blow-back operation?

Thanks gain.

the guns can be jam-a-matic!

This is purely anecdotal, but many years ago I was shooting with a friend at cans. My 9mm would punch holes in whatever can/plastic jug I shot and his 9mm Uzi (16" barrel) would tear it to shreds. Doesn't prove much, but it impressed me. BTW, I've heard, but don't know for sure, that 16" is too long for 9mm - the powder supposedly runs out around 10" or so. That makes sense since it was loaded for pistols. Maybe handloading with slower-burning powder could produce more efficient rounds.

A 9mm is what's on my bedstand, the AR is in the closet. If my neighborhood ever degenerates to the point I even suspect body armor-clad burglers on PCP are a possibility I'm spending my money on real estate agents, not rifle ammo.

Just the one you mentioned (sound). I've heard that isn't an issue when hopped up on adreline but I've never experienced it and I suspect there is a limit to it. I've read that a .223 is less likely to penetrate walls than a 9mm as well, hence the switch from submachine guns by a lot of SWAT teams, but that doesn't concern me (I live in the boonies).

Honestly, short of an "end of the world" scenerio I can't image a situation where you would need to shoot someone at 100 yards in self defense. I couldn't say exactly where the line is, but 100 yards is surely well past it.

". I tried shooting without ear protection just to get a sense of how loud it was and it was very tame. I wouldn't shoot all day without ear protection but for a self defense situation, I can see where it would be nice to not have the deafening noise of a .223 round. "


That is Stupid.  You just put wear on your ears you can never remove.

I have no problem firing a .223 to save my life with no ear protection- I'll have pain for 3-5 shots and then my ears will basically turn off and I won't have any more trouble continuing to fire. That way I may lose a lot of hearing but I will not lose my life.

[b]I'ld prefer to use a sound suppressor and then I will live and keep my hearing[/b]


True advantages of 9mm Ar15/M-16's... They are capable of retaining full power while firing subsonic 158grain ammo and this will allow them to be more effectively suppressed than their .223 counterparts using normal supersonic ammo.  In a pinch I'll bet hitting and killing is possble at 200-300yds with a 9mm ar.  Tracers are great if you have them. I've hit human silouette (little Ivan pop-ups) on the 9mm AT4 trainer range at 300meters with the 9mm tracer training rounds.  These are single shot and sights are crude so I imagine it's easier with an 9mm Colt subgun on semi.

I'd say with the heavy subsonic ammo, you can get the trajectory out to around 300 yards or more. Might take a lot of clicks on the ole' elevation knob to get that POI up there. Does anyone have how many clicks it takes to move the POI up to level with 124 gr. olympic 9mm ammo? I haven't bothered trying to chronograph the stuff, because it is just blasting/ plinking fodder.

I bought a Colt-pattern 9mm upper for my M16 due to several things I percieve to be advantages.

-Cheaper good quality ammo.
-Runs cooler on full auto
-More indoor ranges allow it.  Ever fire 5.56mm from an 11.5" barrel in an enclosed space?  Your ears will BLEED in 4-5 shots without plugs or muffs.
-lookieloos and newbies at the range ususally have 9mm but will mooch 5.56mm.  I like letting newbies shoot whether they have ammo or not but when they bring the 9mm, I'm much more willing.
-Fewer parts to break.
-Much less likely to kaboom my $6000+ preban lower.  That's pre-86, the REAL assault rifle ban.
-More (or less?) bang for the buck with supressors than with 5.56mm.
-9mm is much less inimidating to women and sissies.

Now, I'll whip out the Commando upper when the Elmer Fudds and old guys won't make room on the bench.  It's like spraying Dork-be-gone, except it doesn't make ME leave.  30 rounds of XM193 gets everyone's undividied attention.

Better is relative.

ADDED:
Forget about all that stopping power BS.  It's academic.  9mm goes fast enough out of a 10+ inch barrel to get the job done if you do yours.
An ISPC weenie once told me that the first rule of being a competitive shooter is "You can't miss fast enough".  I think it applies to defending your castle too.

John, I like you, you're funny.... We need to cross paths somewhere and say hi. I do shoot IPSC, and your friend speaks the truth. At our local, the Master makes it a point to tell us "A" + "B" shooters to "make sure and shoot real fast". There is usually 5 of us that razz each other.

If you've got a place to blast a machinegun, I'll do the 5320.20 and come to OH sometime!

I miss the IPSC shooting.  My IPSC shooting days came to an end in 94 when orders to Germany showed up.  Europe is like CA and NJ where everthing fun is either illegal, taxed or takes insurance and permits that you can't obtain or afford.

I'm thinking of really turning my 9mm upper into a spacegun upper with a flippyfloppy front sight, a good brake and one of those crazy ARMS bi-level SIR ribbed thingies.  I might even get a vertical foregrip.  The only bad part of doing that is that I can't look down my nose at the folks who cobble crap all over their pea shooters, for I have seen the enemy and they are me!

About the .223 less likely to penetrate walls thing.  I fired a 55gr soft point at a 3/8" steel spinner at 25yrs that I use for pistol shooting (this spinner is good up to a 44mag)just to see what would happen.  It put a nice clean approximately 30 cal hole through the middle of the spinner.  That tells me that 1/2" of sheet rock some plywood and maybe the occasional 2x4 would barely slow it down.  If you have neighbors or people in other rooms of the house a .223 sounds like a bad idea to me.  That said a FMJ would be even worse for going through six of your neighbors houses before stopping.

I hear what you're saying.  
BUT, it's hard to discredit all this hoopla about the 5.56mm being THE entry/cqb round as opposed to 9mm or 12ga.

9mm FMJ seems to penetrate WAY out of proportion to the actual power of the round.  I've done the wet phone book thing and fired at walls in an old house on an uncle's property and FMJ 9mm was suprisingly dangerous.
Given the odds of a hollowpoint pistol round getting plugged up with crap (sheetrock, leather, gold teeth, denim, etc) it seems like a safe thing to regard all pistol rounds as FMJ.

In my experience, 5.56mm seems to loose an awful lot of steam once it gets destabilized.
There is a big difference in the structural integrity of the projectile you describe and mil-spec 55gr FMJ.  That cannelure is pretty fragile.  Hunting bullets are designed to stay together and military rounds generally aren't.
A 30 round mag of .223 45 gr JSP hunting rounds might not be a better choice than the same mag full of M193 ball.  Who knows?

I figure that if you connect with your target in a bad situation, you're already doing as well as can be hoped for.  That's why I don't spend money on the latest super-duper-fad rounds but stick to known performers like Federal 9BPLE and M193 ball.  Even more so, I try to avoid needing to apply these ideas like I'm sure everyone else does.  No hero here, just us chickens.

Another mis-quote/paraphrase comes to mind here from the Evan Marshall and Evan Sanow book Handgun Stopping Power.  Marshall described the event of hollowpoint expansion as being icing on the cake but not to be relied upon.

On a related side note, a non-shooting coworker asked me if I'd actually fire a gun in my home in self defense.  Naturally, I responed in the affirmative.  He asked, "What about the noise?"
What about the noise?  What about my wife?  What about my ASS?

One of my criminal justice professors recently addressed both of those issues and echoed what you said...

When filled with adrenaline, you don't even hear the gun fire. And, that recent studies showed less penetration through typical residential walls using .223 rather than 9mm.